Method of grinding



S. STEINMETZ METHOD oF GRINDING Aug., w 1924ia Filed Auz. 26 1921Patented Aug. 19, 1924.

PATENT OFFICE.

STEFAN STEINMETZ, F BERLIN, GERMANY.

METHOD or Gamme.

Applicatin led August 26, 1921. Serial No. 495,528.

To all whom 'it may concer/n.:

Be it known that I, STEFAN STEINMn'rz, a citizen of the German Republic,and a resident of Berlin Germany, have invented a Lt certain new anuseful Improved Method of Grindin (for which I have obtained a patent inermany, No. 311,271, October 11, 1917), of which the following is aspecnication. 1

The diiiculty of breaking up bran into,

property of the bran to offer, if to be converted into a very finepowder, a resistance which is the greater the more the state of the bran'durlng the reduction approaches the Hour-free state. The cause for thisphenomenon resides in the bran assummg gradually the form of thin andcurved lamelles which easily slip through the grinding path in generaland the grinding furrows in particular. l The invention is based uponthe cognizance that two features promote the transformation of bran intopowder, viz:

1. The grinding process must be such that, first, the bran remainspreserved in the form of as large scales as possible, because in thiscase the coarseness of the flour produced from the bran'remains tangibleand the starchand gluten-cells are protected from destruction .impairingtheir germinating power.

2. When the bran has been obtained in this known manner, it is convertedinto a very fine powder by two separate mechanical steps consistin inthe bran being rst cut to ieces and en ground down. This may, i desiredor necessary, be continued until the bran has attained a degree offineness which `is even greater than that of the coreflour alreadyobtained.

This manner of operation is preferably carried through by means ofdisk-mills, the disks of which rotate in op-posite directions. The'grinding disks should be covered with pieces of hard cast iron oranother suitable material and said pieces should have furrows or ripplesprovided with sharp, bladelike teeth a apted to act like scissors and tocut the bran to pieces. The sifting after the cutting must be so linealready that only the by far smallest particles pass through.

The remaining particles are preferabl introduced into another mill ofthe same d, but having the disks covered with emery, or with plates oftangible coarseness, by which the pre-worked bran is completely grounddown. The two mills may be combined to one. Sifting the product Aafterthe two workin phases mentioned is preferably effected y air currentscarrying away only the finest particles of the bran, but instead of thismeans ad uately fine sieves may be made use of. 'I e fineness of thegrinding down, controlled b the fine siftin warrants extracting t enutrients stil conaliied in the bran, as well as their digesti- In orderto make my invention more clear I refer to the accompanying drawingwhich explains rather diagrammatically `the transformation of bran intobran dust by means of a disk mill having a double disintegratingsurface. Figure 1 is a vertical transverse section through the mill andshows chiefly a plan of one of the grindin disks; Figure 2 is a verticallongitudina section through this mill.

After the grainhas been freed, preferably on the wet Way, from its cuterstraw skin and the flour core has been extracted y the ordinary grindingprocedure, the bran remaining from this procedure is introduced throughthe hopperv 1 into the mill, the disks 2 and- 3 of which-rotate inopposite directions and are covered with concentric inding rings 4, 6and 5, 7 The rings 4 and 5 are rippled and work together llke a pair ofscissors so that they actually cut the bran. The grinding rings 6 and 7,however, which consist of emery or an equivalent material reduce the cutbran particles to dust which then is conducted to a pneumatic sifter 8or to a sifting machine having adequately ne sieves. The remainders arere-conducted into the mill through the passage 9 where they are treateda second time, and this is, or may be, repeated until the bran has, soto say, been ound dead. The other ortion of the dust 1s retained aftereach si ing and the whole, or, may be, solely its nutritious componenteseparated from it by siftin are, finally added to the flour intended orthe Having now described my invention, what I desire to secure by n.patent of the United igl'rinding the cut lamelles or scales to' mostStates is: nely divided powder. 10

The process of obtaining the nourishing In testimony whereof I aix mysignature `partic1es in bran, consistin' in vfirst separatin presence oftwo witnesses.

5 mg the bran from the gram in the form of STEFAN STEINMETZ.

scales or lamelles, seoondl cutting these Witnesses: scales or lamellesto brin t em into a form Orro T. BRUNN,

other than scales or lame las, and thereafter PAUL Bumm).

